Optical fibers used as a transmission path in an optical communication system are connected to each other by optical connectors as disclosed in Patent Document Nos. 1 and 2. The optical connectors put into practice are an MT (Mechanically Transferable) type optical connector as disclosed in Patent Document No. 1, an MPO (Multi-fiber Push On) type optical connector as disclosed in Patent Document No. 2 or others, for example.
The MT type optical connector includes, as main elements, a first connector plug connected to one group of optical fibers, a second connector plug connected to the other group of optical fibers and a locking mechanism for holding the first connector plug and the second connector plug, while positioning connection end surfaces of the respective optical fibers projected from end surfaces of ferrules of the respective connector plug to each other so that the connection end surfaces are brought into contact or close to each other.
The locking mechanism is required to hold the first and second connector plugs in a state wherein the connection end surfaces of the respective group of optical fibers are brought into contact or close to each other so that the transmission efficiency and the optical connection characteristics are favorably maintained.
As a locking mechanism, for example, as shown in Patent Document No. 1, a clamp spring disposed while straddling over the first and second connector plugs connected each other as a whole is proposed. The clamp spring is formed in a flat plate shape, having curved pressed portions at positions corresponding to rubber boots of the first and second connector plugs at a predetermined distance therebetween. The pressed portions bias the rubber boots of the first and second connector plugs in the direction that come close to each other by the resilience of the pressed portions.
When the clamp spring is mounted on the first connector plug and the second connector plug connected to each other, the first connector plug and the second connector plugs are forcibly pushed into a gap between pressing portions of the clamp spring opposed to each other against the elastic force of the pressing portions. Thereby, the clamp spring biases the end portions of the first connector plug and the second connector plug encircled by the rubber boots so that the ferrules of the first connector plug and the second connector plug opposed to each other move closer to each other in an axial direction of the optical fibers. Accordingly, the first connector plug and the second connector plug are in a locked state while keeping the connection ends surfaces of the respective groups of optical fibers being brought into contact or close to each other.
On the other hand, when the clamp spring is detached from the first connector plug and the second plug connected to each other, the clamp spring is forcibly separated from the first connector plug and the second connector plug against the frictional force caused by the elastic force of the respective pressed portions.
Patent Document No. 1: Japanese Patent Gazette No. 3566881
Patent Document No. 2: Japanese Patent Gazette No. 03432394